Volume 10, Issue 4, Pages 431-438 (April 1999) Neutralizing Antibodies Have Limited Effects on the Control of Established HIV-1 Infection In Vivo  Pascal Poignard, Rebecca Sabbe, Gaston R Picchio, Meng Wang, Richard J Gulizia, Hermann Katinger, Paul W.H.I Parren, Donald E Mosier, Dennis R Burton  Immunity  Volume 10, Issue 4, Pages 431-438 (April 1999) DOI: 10.1016/S1074-7613(00)80043-6

Figure 1 Plasma Levels of HIV-1 RNA Measured by Quantitative RT-PCR in HIV-1-Infected hu-PBL-SCID Mice after Administration of the Neutralizing Ab b12 Hu-PBL-SCID mice with a HIV-1JR-CSF (squares) or HIV-1SF162 (circles) isolate infection were injected i.p. with 1 mg of b12 (solid symbols) or control Ab (open symbols). Mice received a single injection at day 0 (A and B) or multiple injections at days 0, 5, and 10 (C and D). In (A) and (B), mice were treated 6 days after viral infection. In (C) and (D), mice were treated when viral steady state was reached, 8 and 10 days after viral infection for HIV-1SF162 and HIV-1JR-CSF, respectively. The vertical arrows indicate days of Ab injection. Each curve represents the values for a single animal. Blood was obtained by bleeding from the orbital sinus of the mice. Plasma HIV-1 RNA levels were measured by the quantitative Roche RT PCR assay (Amplicor HIV Monitor, Roche Molecular Systems), following the manufacturer’s recommended protocol, except that plasma volume was 100 μl. The limit of HIV-1 RNA detection, as indicated by the horizontal arrow, was 400 copies/ml. Immunity 1999 10, 431-438DOI: (10.1016/S1074-7613(00)80043-6)

Figure 2 In Vitro Neutralization of HIV-1 Isolates Rescued from b12-Treated hu-PBL SCID Mice In vitro neutralization by mAb b12 of isolates rescued from HIV-1JR-CSF (squares)- or HIV-1SF162 (circles)-infected hu-PBL-SCID mice, treated previously with mAb b12 (solid symbols) or control Ab (open symbols, inset graphs). Immunity 1999 10, 431-438DOI: (10.1016/S1074-7613(00)80043-6)

Figure 3 Plasma Levels of HIV-1 RNA in HIV-1-Infected hu-PBL-SCID Mice after Anti-CD4 Ab Administration The horizontal arrow indicates the limit of HIV-1 RNA detection (400 copies/ml). Each curve represents the values for a single animal. (A) Hu-PBL-SCID mice with an established HIV-1JR-CSF isolate infection were injected intraperitoneally at day 0 with 1 mg of OKTcdr4A (solid symbols) or control Ab (open symbols). (B) Hu-PBL-SCID mice with an established HIV-1SF162 isolate infection were injected intraperitoneally at day 0 with 1 mg of OKTcdr4A (solid symbols) or were left untreated (open symbols). Immunity 1999 10, 431-438DOI: (10.1016/S1074-7613(00)80043-6)

Figure 4 Treatment of HIV-1JR-CSF-Infected hu-PBL-SCID Mice with a Cocktail of Neutralizing Abs (A) Plasma levels of HIV-1 in HIV-1JR-CSF-infected hu-PBL-SCID mice after administration of a cocktail of neutralizing Abs (b12, 2G12, and 2F5). Ab was administered 11 days after viral infection. The time of Ab injection is indicated by the arrow at day 0 in the figure. Each curve represents the values for a single animal. M1 and M2 indicate the mouse from which the isolates T1 and T2 were rescued, respectively. Plasma HIV-1 RNA levels were measured by the quantitative Roche RT PCR assay (Amplicor HIV Monitor, Roche Molecular Systems), using a plasma volume of 50 μl. The limit of detection, as indicated by the horizontal arrow, was 800 copies/ml. (B) In vitro neutralization by (1) 2F5, (2) 2G12, and (3) b12 of the challenge virus HIV-1JR-CSF (closed square) and the viral isolates T1 (closed triangle) and T2 (open triangle) isolated from infected hu-PBL-SCID mice following treatment with a cocktail of the Abs 2F5, 2G12, and b12 (see [A]). (C) Deduced amino acid sequence of the C3, V4, and gp41 regions of gp160 from wild-type (WT) JR-CSF virus and escape variants T1 and T2 following triple Ab therapy (see [A] and [B]). Immunity 1999 10, 431-438DOI: (10.1016/S1074-7613(00)80043-6)

Figure 5 Interplay between Wild-Type and Neutralization Escape Viruses upon Ab Treatment The C4 to V4 region of gp120 that includes mutations consistent with b12 and 2G12 escape was amplified and sequenced from plasma viral RNA from the T1 variant (Figure 4) taken at different time points. The bars represent the percentage of clones displaying either the wild-type sequence (gray) or the escape mutant sequence (black). The number of clones sequenced was 5, 4, 11, and 12 at day 0, 5, 7, and 13, respectively. The line represents the approximate Ab concentration (b12 concentration = 2G12 concentration) in the mouse plasma estimated from the known pharmacokinetics of the Abs and checked as total Ab concentration at initial and mid-point by ELISA reactivity with gp120. Immunity 1999 10, 431-438DOI: (10.1016/S1074-7613(00)80043-6)